US 7,064,037 B2 · Silicon-germanium virtual substrate and method of fabricating the same

Abstract

A method of forming a relaxed silicon-germanium layer for accommodation of an overlying silicon layer formed with tensile strain, has been developed. The method features growth of multiple composite layers on a semiconductor substrate, with each composite layer comprised of an underlying silicon-germanium-carbon layer and of an overlying silicon-germanium layer, followed by the growth of an overlying thicker silicon-germanium layer. A hydrogen anneal procedure performed after growth of the multiple composite layers and of the thicker silicon-germanium layer, results in a top composite layer now comprised with an overlying relaxed silicon-germanium layer, exhibiting a low dislocation density. The presence of silicon-carbon micro crystals in each silicon-germanium-carbon layer reduces the formation of, and the propagation of threading dislocations in overlying silicon-germanium layers, therefore also reducing extension of these defects into an overlying silicon layer, wherein the tensile strained silicon layer will be used to accommodate a subsequent device structure.

Claims27

Dependent claims

A method of forming a semiconductor layer with tensile strain, comprising the steps of:

providing a semiconductor substrate;
forming a first type semiconductor alloy layer on said semiconductor substrate;
forming a second type semiconductor alloy layer on said first type semiconductor alloy layer, resulting in a composite layer comprised of overlying, said second type semiconductor alloy layer on said first type semiconductor alloy layer;
forming multiple composite layers on underlying said composite layer, with each composite layer of said multiple composite layers comprised with an overlying second type semiconductor alloy layer and of an underlying first type semiconductor alloy layer;
forming a thick second type semiconductor alloy layer;
performing an anneal procedure insitu in an hydrogen ambient resulting in an overlying composite layer comprised with a relaxed second type semiconductor alloy layer;
and
forming said semiconductor layer via LPCVD or MBE procedures wherein said semiconductor layer is formed under tensile strain on underlying, said thick second type semiconductor alloy and wherein said semiconductor layer is formed in same apparatus used for formation of said thick second type semiconductor alloy layer and for said anneal procedure.

5 more elements

Dependencies are inferred from the claim text.

Silicon-germanium virtual substrate and method of fabricating the same

Life of this patent

Silicon-germanium virtual substrate and method of fabricating the same

Life of this patent

Abstract

Claims27